| 摘要 |
PURPOSE:To execute a detection of a trunk detached from a switchboard, by keeping pace with a state supervising operation of the trunk, by providing a means for sending back simultaneously a supervised point information and an operation confirming information to a trunk scanner, in the trunk. CONSTITUTION:When a start signal is generated to an SDVO lead from a trunk scanner TSCN, a supervisory point information SCN of an output from a state supervising circuit is sent out to a related trunk TR through an AND circuit ICO, and an inversion logic of this information is sent out as a confirming information PTY to the TSCN through an NAND circuit IC1. The TSCN stores the information SCN of a receiving signal in a storing circuit IC4, discriminates normality of the receiving signal by logical circuits IC20-27, and stores it in a storing circuit IC3. In case when voltage levels of the information SCN and the information PTY coincide with each other, its TRK is considered to be unmounted to a switchboard, and a high level logic is stored in the circuit IC3. A common operating device receives an information of the circuit IC3, and discriminates an unmounted TRK. |
